The present invention relates to the art of air filter systems and, more particularly, to an improved vacuum cleaner employing a novel filter system. The invention is particularly applicable for a canister type vacuum cleaner and it will be described with particular reference thereto; however, the invention has much broader applications and may be used to filter air by employing the novel filter system and filtering method as contemplated by the present invention.
U.S. Pat. Nos. 5,248,323; 5,515,573; 5,593,479; 5,603,741; 5,641,343; 5,651,811; 5,658,362; 5,837,020; 6,090,184; and Des. 432,746 are incorporated herein as background information regarding the type of cleaning systems to which the present invention is particularly applicable, and to preclude the necessity of repeating structural details relating to such cleaning systems. Several of these patents illustrate a canister type vacuum cleaner with a low velocity receptacle or chamber into which is placed a conical filter sheet formed from non-woven cellulose fiber placed over a downwardly extending support structure for the purpose of removing particulate material from the air flowing through the vacuum cleaner. The rigid perforated conical support structure or member holds the filter sheet in its conical configuration. The support member and filter sheet are mounted together with the layer covering the rigid support member. Within the conical support member there is provided a generally flat disc shaped cellulose filter sheet for further removal of particulate solids as the solids pass with the air from the canister through the conical filter sheet and through the disc to the outlet or exhaust of the vacuum cleaner.
As more people populate urban environments, there is an increasing need to provide a clean air environment at home and in the work place. In urban areas, where pollution levels sometimes exceed maximum values set by the EPA, the need for a clean air environment becomes even more apparent. In view of the posed hazards these polluted environments create, the public has demanded a means for removing pollutants from the environment to provide a healthy environment for both living and working. Furthermore, many particles in the air can act as irritants and/or increase or aggravate a person""s allergies. Airborne pollutants can also contribute to respiratory infections and illnesses which can be hazardous to individuals with respiratory problems. Particles in the air can also create problems such as burning eyes, nose and throat irritation; cause or contribute to headaches and dizziness, and/or cause and/or contribute to coughing and sneezing. Furthermore, these particles can include various types of spores, dust mites, micro-organisms, such as bacteria and/or viruses, and/or other types of harmful particles which may cause serious illness or infection to a person.
In an effort to reduce the number of particles from the air and/or other environments, many homes, offices, and buildings have incorporated a central filtering system to remove particles entrained in the air. Unfortunately, these systems are very expensive and/or do not remove many of the small particles which can be the most hazardous and irritable to persons, such as spores, micro-organisms, such as bacteria and/or viruses, dust mites and some harmful chemicals. Typically, these filtering systems only remove about 300,000 particles out of about 20 million particles which flow into the filter medium. The small particles, which make up a majority of the particles in the air, freely pass through these conventional filter systems and are recirculated through the home and/or office.
In an effort to remove particles from a home and/or office environment, and reduce the amount of particles recirculated during the vacuuming of the home and/or office, two design strategies have been developed by Assignee, one relating to the design of the vacuum cleaner and the second relating to the design of the filters. Assignee has found that canister type vacuum cleaners provide superior cleaning efficiencies as compared with upright vacuum cleaners. One particular canister type vacuum cleaner is illustrated in U.S. Pat. No. 5,248,323, which is incorporated herein by reference. The canister type vacuum cleaner includes a reduced or low velocity chamber with a high velocity air inlet. Air is drawn into the low velocity chamber by an electric motor which drives a rotary fan. The rotary fan creates a vacuum in the low velocity chamber to draw air laden with particulate material through the chamber and to blow the filtered air through an outlet in the motor housing as exhausted clean air. Canister type vacuum cleaners normally include a cylindrical or a conical cellulose filter extending downwardly into the canister or low velocity chamber. The filter is typically formed of a porous mat to remove dirt and debris carried by the air drawing into the low velocity chamber. The high velocity air drawn into the chamber has entrained large solid particles. The large particles which are brought into the low velocity chamber are swirled or vortexed in a centrifuge configuration with convolutions so that the large particles are extracted by the vortexed or cyclonic action of the air in the canister. Thereafter, the air is pulled through the filter toward an upper motor that drives a fan which creates a vacuum in the canister or low velocity chamber. The fan then expels the filtered air outwardly through an exhaust passage, or passages, above the canister. A filter, such as a thin filter disc, is provided between the conical filter and the fan to prevent large particulate material that is inadvertently passed through the cylindrical or conical filter from contacting the fan. The ""323 patent discloses the use of an activated charcoal containing filter to efficiently remove gaseous impurities in the air, such as paint fumes and other odor creating gases.
The canister type vacuum cleaner, as so far described, though exhibiting improved cleaning efficiencies as compared with upright vacuum cleaners, only removes relatively large particles entrained in the air. Many of the air particles of a size less than 10 microns pass freely through the filter medium and are recirculated in the room. These small particles can act as irritants to an individual and the recirculation of such particles can increase such irritation to an individual. High density filters can be used to filter out these very small particles in the air; however, high density filters cause large pressure drops through the filter and thus cannot be cost effectively used in standard vacuum cleaners.
The filter system disclosed in U.S. Pat. Nos. 5,593,479 and 5,651,811 addresses the problem of filtering small particles by disclosing a multi-layer filter which includes at least one layer of electrically charged fiber material encapsulated between at least two layers of support material. The multi-layer filter effectively removes small particles from the air which penetrate the cellulose fiber layer. The multi-layer filter is a specialized filter developed to remove many of the small particles in the air. Such filters are known as HEPA filters, High Efficiency Particle Air Filters, which, by government standards, are filters with a minimum efficiency of 99.97%. The industry defines HEPA filters as those which are efficient in removing 99.97% of the airborne particles having the size of 0.3 micron or larger. HEPA filters are commonly used in ultra clean environments such as in a laboratory, in electronic and biologically clean rooms, in hospitals, and the like. HEPA filters have recently been incorporated in air filters for business and individual use. The ""479 and ""811 patents disclose that an activated charcoal filter can also be used to remove odors from the air.
The multiple filter system disclosed in the ""479 and ""811 patents was further improved by the filter system disclosed in U.S. Pat. No. 6,090,184. The filter system disclosed in the ""184 patent combined an electrically charged fiber material with an activated charcoal filter to simplify the use of the filters in the vacuum cleaner. The combined filter reduced the number of filters to only the standard cellulose filter and the combined gas and small particle filter. The combined filter was designed to exhibit increased filter efficiency without added pressure drop. The efficiencies of standard HEPA filters are all based upon 0.3 micron size particles. Historically, it was believed that particles about 0.3 micron in size were the most difficult to remove from the air. However, particle filtration testing revealed that particles the size of about 0.1 micron are the most difficult to remove from the air. Standard HEPA filters do not efficiently remove such small particles and allow such particles to freely pass through the filter medium. An analysis of these small particles has shown that the particles do not naturally fall out of the air, but instead remain entrained in the air by constantly bouncing off other particles in the air (i.e. Browning effect). These small particles have also been found to deviate from the air flow thus making such particles even more difficult to remove from the air. The filter disclosed in the ""184 patent was designed to remove at least about 99.98% of the particles in the air that were about 0.1 micron or greater in size.
Although Assignee""s vacuum cleaners and filter systems effectively and efficiently remove particles entrained in the air, there is a continued demand for more efficient vacuum cleaners and more user friendly vacuum cleaners.
The present invention relates to an improved air filtering system and, more particularly, to a vacuum cleaner with a novel filtering system which allows the vacuum cleaner to efficiently and effectively remove particles and/or unwanted odors or gases from the environment. In one embodiment, the improved filtering system is used in a cyclonic type vacuum cleaner such as, but not limited to, a canister type vacuum cleaner, to handle a wide variety of particles entrained in the air being drawn through the vacuum cleaner. In another embodiment, the filtering system is designed to remove odors from the air as the air passes through the filtering system. In essence, the filtering system can be used in an environmental air cleaning device as well as a standard vacuum cleaner.
In accordance with the present invention, there is provided an improvement in a vacuum cleaner of the type comprising a reduced or low velocity chamber with a high velocity air inlet, a motor, a rotary device driven by the motor to create a vacuum in the low velocity chamber, an outlet for exhausting air from the low velocity chamber, and a filtering system positioned at least partially in the low velocity chamber for removing solid particles from the air. In one embodiment, the filtering system includes one or more changeable and/or disposable filters. In one aspect of this embodiment, at least one of the filters removes most sizes of particles including particles of less than about ten microns in size. Such a filter provides a significantly cleaner environment. Standard filter mediums filter out approximately 300,000 particles out of 20 million particles which flow into the filter medium. Particles which are ten microns or less in size pass freely through a standard filter medium. Such particles include pollen, dust mites, bacteria, viruses, etc. The recirculation of these small particles can spread diseases and/or cause allergic reactions. The filtering system of the present invention includes a filter which removes a majority of sizes of particles entrained in the air. In a typical vacuuming operation, nearly 20 million particles are directed into the vacuum cleaner. The filtering system removes at least about 18-19 million of these particles. As a result, over 90% of the particles greater than 2 microns in size are filtered out of the air passing through the improved filtering system. The filtering system can include mechanical, electrical (which includes electrostatics) and/or chemical mechanisms to filter out the particles. In another embodiment, the filtering system is designed to remove odors from the air. In one aspect of this embodiment, the filtering system incorporates the use of a gas absorbing substance to absorb odors that are drawn into the vacuum cleaner.
In accordance with another aspect of the present invention, the filtering system includes one or more particle filters which removes at least about 99.97% of the particles entrained in the air having a size greater than about 0.3 micron. In one embodiment, the particle filter removes at least about 99.98% of the particles entrained in the air having a size greater than about 0.1 micron. In another embodiment, the particle filter is made of one or more filter layers. In aspect of this embodiment, the particle filter is a single filter made of multiple filter layers. In another aspect of this embodiment, the particle filter is a plurality of single layer filters. In still another aspect of this embodiment, the particle filter is a plurality of filters, which filters are single layer filters and/or multiple layer filters. In still another embodiment, the particle filter removes particles from the air mechanically, chemically and/or electrically. In yet another embodiment, the composition of the particle filter includes, but is not limited to, the composition of particle filters disclosed in U.S. Pat. Nos. 5,248,323; 5,593,479; 5,641,343; 5,651,811; 5,837,020 and 6,090,184, which are incorporated herein by reference. In still yet another embodiment, the configuration or design of the particle filter includes, but is not limited to, the configuration or design disclosed in U.S. Pat. Nos. 5,248,323; 5,593,479; 5,641,343; 5,651,811; 5,837,020 and 6,090,184, which are incorporated herein by reference.
In accordance with still another aspect of the present invention, the filtering system includes one or more gas filters to remove undesired gases and/or odors from the filtered air such as, but not limited to, smoke, fumes, gas contaminants, and/or noxious gases. In one embodiment, the gas filter includes a gas absorbing substance. In one aspect of this embodiment, the gas absorbing substance includes, but is not limited to, activated carbon, activated charcoal, diatomaceous earth, Fuller""s earth, volcanic rock, lava rock, and/or baking soda. In another embodiment, the gas filter includes one or more mats, or woven and/or non-woven materials impregnated with one or more gas absorbing substances. In one aspect of this embodiment, the average particle size of the gas absorbing substance, when impregnated on and/or in a material, is generally less than about 10 mesh, and typically less than about 100 mesh; however, larger particles can be used. In another aspect of this embodiment, the mat includes a non-woven polyester material. In another aspect of this embodiment, the material has a sponge-like texture. In still another aspect of this embodiment, the material has a thickness of about 0.001-1 inch. In still another aspect of this embodiment, the one or more gas filters also filter particles from the air as the air passes through the gas filter(s). In yet another embodiment, one or more gas filters include one or more gas absorbing substances in the form of a resin and/or granules. In one aspect of this embodiment, the resin and/or granules are contained in an air permeable device such as, but not limited to, a ventilative bag, a ventilative container and/or the like. In still yet another embodiment, the one or more gas filters include one or more gas absorbing substances impregnated in a textile material. In a further embodiment, the gas filter(s) and particle filter(s) are oriented such that at least one particle filter or filter layer filters particles prior to exposing the filtered air to the gas filter(s). In yet a further embodiment, the gas filter(s) and particle filter(s) are oriented such that at least one gas filter or gas filter layer absorbs gas prior to exposing the gas filtered air to the particle filter(s).
In accordance with yet another aspect of the present invention, the filtering system includes a particle filter for removing small particles that includes at least one section designed to be a high efficiency particle removing section to remove very small particles from the air passing through the filter. This section can use mechanical and/or electrical (including electrostatic) capture mechanisms to remove particles entrained in the air. This section can include one or more layers. If more than one layer is used, the layer can be connected together by adhesive, stitching, staples, clamps, melted regions, and/or the like. In one embodiment, the particle filter is pliable so that the section easily conforms to and/or deforms on a surface, such as when the particle filter is subjected to suction. In one aspect of this embodiment, the deformation of the particle filter results in the filter having one or more ribs and one or more recessed sections between the ribs. In another embodiment, the particle filter has a generally conical shape.
In accordance with still another aspect of the present invention, the filtering system includes a gas filter having at least one section for removing odor and gas from the air passing through the filter. This section can use chemical, mechanical and/or electrical (including electrostatic) capture mechanisms to remove odors and/or undesired gas the air. This section can include one or more layers. If more than one layer is used, the layer can be connected together by adhesive, stitching, staples, clamps, melted regions, and/or the like. In one embodiment, the gas filter is pliable so that the section easily conforms to and/or deforms on a surface, such as when the gas filter is subjected to suction. In one aspect of this embodiment, the deformation of the gas filter results in the gas filter having one or more ribs and one or more recessed sections between the ribs. In another embodiment, the gas filter has a generally conical shape.
In accordance with still yet another aspect of the present invention, the filtering system includes a particle/gas filter for removing small particles that includes at least two distinct sections. One section of the particle/gas filter is designed to be a high efficiency particle removing section to remove very small particles from the air passing through the filter. This section uses mechanical and/or electrical (including electrostatic) capture mechanisms to remove particles entrained in the air. This section can include one or more layers. The second section of the particle/gas filter is designed to be a gas removal section to remove unwanted gases from the air. This second section can be designed to also remove particles from the air. The second section uses electrical (including electrostatic), mechanical and/or chemical capture mechanisms to remove gases and/or particles from the air. The second section can be comprised of one or more layers. In one embodiment, the two sections are connected together. In one aspect of this embodiment, at least two of the sections are connected together by adhesive, stitching, staples, clamps, melted regions, and/or the like. In one specific design, at least two of the sections include a hot melt adhesive to at least partially connect the sections together. In another embodiment, one or more of the sections is pliable so that the sections easily conform to and/or deform on a surface, such as when the sections are subject to suction. In still another embodiment, one or more of the sections is rigid or semi-rigid so as to resist being deformed, especially when exposed to suction. The improved particle/gas filter removes small particles and odors in the air as the air passes through the filter, thus eliminating the need for a separate filter for small particle removal and odor removal. The two sections of the particle/gas filter are connected together to maintain the integrity of the sections during operation and to minimize the degree of pressure drop through the filter. In still another embodiment, the orientation of the filter sections is such that the filter section filters particles prior to exposing the filtered air to the gas absorbing substance in another filter section. Alternatively, the orientation of the filter sections is such that the filter section absorbs gas by the gas absorbing substance prior to exposing the filtered air to particle filtration of another filter section. Alternatively, the orientation of the filter sections is such that the filter section absorbs gas by the gas absorbing substance and filters particles at substantially the same time prior to exposing the filtered air to another filter section.
In accordance with a further aspect of the present invention, the filtering system includes a filter that has a support material and fiber material. In one embodiment, the fiber material is an electrically charged material that is adapted to attract particles to the fibers as particle-entrained air pass adjacent the fibers. In one aspect of the embodiment, the fiber material forms at least one filter layer. In another aspect of this embodiment, the fiber material is a non-woven material. In still another aspect of this embodiment, each layer of the fiber material has a weight of about 30-180 gm/m2. In yet another embodiment, the support material is a durable material used to maintain the integrity of the fiber material. In one aspect of this embodiment, the support material at least partially supports and maintains the fiber material in position during the air filtration process. In another aspect of this embodiment, the support material is a woven material such as, but not limited to, cotton, nylon, rayon, and/or polyester. In still another aspect of this embodiment, the support material at least partially encapsulates the fiber material. In another embodiment, the at least one layer of support material and at least one layer of fiber material are connected together by adhesive, stitching, staples, clamps, melted regions, and/or the like.
In accordance with still another aspect of the present invention, a disposable cellulose filter is used to remove large particles entrained in the air. The cellulose filter can be used alone or in combination with one or more other filters. In one embodiment, the cellulose filter is positioned in the air path such that the particle entrained air passes through the cellulose filter prior to the air contacting a filter designed to remove very small particles and/or gas. The use of the cellulose filter enhances the life of the one or more other filters in the filtering system.
In accordance with yet another aspect of the present invention, one or more filters in the filtering system are cylindrical, conical or semi-conical in shape to increase the surface area of the filter(s) thereby providing increased particle removal.
In accordance with still yet another feature of the present invention, the filtering system minimizes the degree of pressure drop as the air passes through the filtering system. The relatively low pressure drop through the filtering system enables the filtering system to be used in vacuum cleaners, such as canister type vacuum cleaners or in various other types of air filter systems. In addition, the lower pressure drop allows the vacuum cleaner to use a smaller motor so that the vacuum cleaner can have a more compact and portable design, utilize less energy, and/or generate less noise.
In accordance with another aspect of the present invention, one or more filters of the filtering system include one or more tabs, loops or the like, to facilitate the ease in which the filter(s) can be positioned in the vacuum cleaner and/or removed from the vacuum cleaner. The tabs, loops, etc., may also be used as an indicator for the proper position of the filter(s) and/or include information about the filter(s).
In accordance with yet a further aspect of the present invention, the motor of the vacuum cleaner is at least partially located within a motor housing to draw air through an air intake and into the low velocity chamber of the vacuum cleaner, through one or more filters of the filtering system, and to expel the filtered air out through the air exhaust. In one embodiment, the motor includes an electric motor which drives a blade that creates a vacuum in the low velocity chamber, which in turn results in air being drawn into the air intake and through the one or more filters of the filtering system. In another embodiment, one or more filters of the filtering system are disposed between the air intake and the low velocity chamber of the vacuum cleaner to remove a wide variety of particles and/or gases in the air.
In accordance with another aspect of the present invention, a support mechanism is employed to maintain one or more of the filters of the filtering system in a proper position in the vacuum cleaner and/or to support the one or more filters during the filtration of the air. The support mechanism can be incorporated into the filters themselves and/or can be an external mechanism such as a frame. The support mechanism can be one or more pieces. In one specific design, the support member is one piece. In another specific design, the support member is two pieces connected together by bolts, screws, clips, lock tabs, and/or the like. The support mechanism is designed to position and/or to support the one or more filters without impairing the air flow through the one or more filters. In one embodiment, the support mechanism includes a support member having a generally cylindrical or conical shape. In one aspect of this embodiment, the outer perimeter of the support member has a profile and shape that is substantially the same as the profile and shape of the surface of at least one filter so as to substantially fully support the filter. In one specific design, the support member is at least partially nested in at least one filter. In another specific design, at least one filter is at least partially nested in the support member. In another aspect of this embodiment, the outer perimeter of the support member has a profile and shape that is smaller than the profile and shape of the surface of the filter so as to cause the filter to at least partially collapse onto the support member when air is drawn through the filter. In one specific design, the support member is nested in at least one filter and the at least one filter at least partially collapses on the support member during the operation of the vacuum cleaner. In another embodiment, the support mechanism includes a support member having a plurality of fin sections. In one aspect of this embodiment, a plurality of the fin sections are spaced apart from one another. In one specific design, the fin sections are generally symmetrically positioned apart from one another. In another aspect of this embodiment, the outer surface of the fin sections forms a generally cylindrically shaped or conically shaped support member. In still another aspect of this embodiment, at least one opening exists between at least two adjacently positioned fin sections. In still another embodiment, the support member includes at least one rigidity arrangement that at least partially extends between at least two adjacently positioned fin sections. In one aspect of this embodiment, the rigidity arrangement includes at least one rigidity panel. The rigidity panel provides structural rigidity to the support member thereby inhibiting or preventing deformation of the support member during operation of the vacuum cleaner. In another aspect of this embodiment, at least one rigidity panel is positioned between all adjacently portioned fin sections. In yet another aspect of this embodiment, at least one rigidity panel is positioned at least closely adjacent to the rim of the support member. In one specific design, one or more of the rigidity panels are at least partially recessed from the outer peripheral edge of the fin sections. In another specific design, one or more rigidity panels are at least partially flush with the outer peripheral edge of the fin sections. In yet another aspect of this embodiment, the rigidity arrangement includes a rim that connects a plurality of fin sections together. The rim provides structural rigidity to the support member thereby inhibiting or preventing deformation of the support member during operation of the vacuum cleaner. In one specific design, the rim connects all the fin sections together. In another specific design, the rim includes a lip to provide ease of handling the support member, increased structural rigidity, and/or improved sealing. In still another aspect of this embodiment, the rigidity arrangement includes at least one rigidity ring. Like the rigidity panel and rim, the rigidity ring provides structural rigidity to the support member thereby inhibiting or preventing deformation of the support member during operation of the vacuum cleaner. In a further aspect of this embodiment, the rigidity ring is positioned between the rim and the base of the support member. In one specific design, the rigidity ring is positioned at or close to the mid point between the base and rim of the support member. In another specific design, at least one rigidity panel extends upwardly from the rigidity ring and toward the rim of the support member. In yet another embodiment, the support mechanism includes a sealing arrangement to inhibit or prevent air from circumventing through one or more filters of the filtering system and support member. Air that enters the vacuum cleaner is drawn through one or more filters of the filtering system and through the support member. Any air that circumvents the one or more filters of the filtering system will not be properly filtered. The sealing arrangement is designed to help ensure that most, if not all, of the air entering the vacuum cleaner is directed through one or more filters of the filtering system and through the support member. In one aspect of this embodiment, the sealing arrangement includes a sealing ring. The sealing ring is typically made of a plastic and/or rubber material; however, other materials can be used. In one specific design, the sealing ring is placed on and/or secured to the rim of the support member. The sealing ring forms a seal between the support member and low velocity chamber of the vacuum cleaner when the support member is inserted into the low velocity chamber. The sealing ring causes air entering the low velocity chamber to pass through the one or more filters of the filtering system that are positioned adjacent the support member.
In accordance with still another aspect of the invention, the filtering system includes at least one filter having a filter profile that reduces the quantity of large particles entering the low velocity chamber of the vacuum cleaner that are being entrapped, caught, or otherwise embedded on at least one of the filters. This reduction in the number of large particles being entrapped on one or more of the filters during the vacuuming process increases the life and efficiency of the filtering system. In one embodiment, at least one of the filters includes a rib and trough profile on the outer peripheral surface of the filter. The rib and trough profile can be a rigid or semi-rigid structure of the filter, or be a result of the deformation of the filter during the vacuuming process. Typically, the surface area of the trough portion of the filter is greater than the surface area of the rib portion of the filter. The one or more ribs are designed to function as a first contact barrier to particles entrained in the air. The larger particles in the air, upon contact with the one or more ribs, are stopped or reduced in velocity by the one or more ribs. The stopping or reduction in velocity of large particles causes the particles to drop out of the entrained air and onto the base of the low velocity air chamber. Due to the relatively small surface area of the rib portion of the filter, the larger particles have less area to stick to, thus fall off. In addition, since the ribs are exposed to the air first, larger particles that have stuck to the ribs are subsequently knocked off by other particles. Consequently, the larger particles are knocked out of the air prior to the air contacting the trough portion of the filter. The reduction of particles in the air results in the filter having a longer life. In another embodiment, the filter having the rib and trough profile is exposed to a circular or cyclonic air stream. This type of air path is typically produced in canister type vacuum cleaners. The circular or cyclonic air stream causes the particle entrained air to contact the side and front of the rib portions of the filter prior to the air contacting the trough portion of the filter since the rib portions extend farther out into the air stream path than the trough portions. In still another embodiment, the filter having the rib and trough profile has a generally cylindrical or conical shape. In yet another embodiment, the support arrangement includes a support member that is nested in at least one filter of the filtering system. The filter can be a particle and/or gas filter. The support member can be nested in more than one filter, such as two or more filters are nested together, and the support member is nested in the two or more nested filters. When one filter is used, typically the filter is a particle filter or includes a particle filtering section. When more than one filter is used, typically at least one of the filters is a particle filter or includes a particle filtering section. The support member typically has a shape and size that is equal to or smaller than the shape and size of the one or more filters being supported. In one aspect of this embodiment, the support member has a smaller shape and size as compared to the filter to be supported. In addition, the support member has a plurality of fins that are spaced apart from one another. This fin structure of the support member results in a flexible filter to deform onto the fin structure when exposed to a vacuum. The fin structure of the support member causes the filter to form ribs, and the spacing between the fins allows the filter to form troughs between the fins.
In accordance with still yet another aspect of the invention, the filtering system includes a safety filter to prevent large particles from entering the motor section of the vacuum cleaner and/or contacting the motor fan. During the operation of the vacuum cleaner, the particle filter may be damaged during use of the vacuum cleaner and/or from improper installation. For instance, large particles such as, but not limited to, glass pieces, nails, tacks, rocks, etc., may contact the filter and puncture and/or cut the filter. As a result of this damage to the filter, larger particles can thereafter pass through the filter and into the motor chamber of the vacuum cleaner thereby resulting in damage to the motor and/or fan, and/or the clogging of the air exhaust of the vacuum cleaner. Alternatively, the particle filter(s) may be inadvertently left out of the vacuum cleaner or improperly inserted in the vacuum cleaner thus allowing particles to enter the motor chamber. The safety filter is designed to inhibit or prevent such particles from entering the motor chamber. In one embodiment, the safety filter is designed to remove primarily larger particles and allow smaller particles to pass there through. Such a design allows the filter to be made of a less dense material so as to not significantly contribute to pressure drop through the filtering system. In another embodiment, the safety filter is a conically or a cylindrically shaped filter. In still another embodiment, the safety filter is designed to be inserted into an inner region of the support member of the support arrangement. In such a design, the outer peripheral surface of the support member supports one or more filters of the filtering system and an inner region of the support member receives the safety filter. Typically, the safety filter has generally the same shape as the shape of the outer peripheral surface of the support member and/or the one of more filters supported by the outer peripheral surface of the support member; however, the safety filter can have other shapes. In yet another embodiment, the safety filter is held in position in the support member by a filter support. The filter support can also maintain the shape of the safety filter during the vacuum process so as to minimize or prevent deformation of the safety filter. In one specific design, the filter support is nested in the safety filter while the safety filter nests in the support member. In another specific design, the filter support allows for easy removal and replacement or cleaning of the safety filter. In another design, the safety filter and filter support are at least partially entrapped between two or more pieces of the support member.
In accordance with a further aspect of the invention, the filtering system includes a post exhaust gas filter. The post exhaust gas filter is designed to remove undesired gases and/or odors such as, but not limited to, smoke, fumes, gas contaminants, and/or noxious gases from the filtered air after the filtered air exits the motor section of the vacuum cleaner. In past vacuum cleaner designs, all the filters were positioned upstream from the motor section, and the filtered air was blown directly out of the motor section and into the environment. As a result, odors caused from the operation of the vacuum motor were expelled from the vacuum cleaner. The positioning of the post exhaust gas filter at a location after the filtered air exits the motor section allows the gas filter to absorb odors caused by the motor and any odor that may have penetrated the other filters of the filtering system. Consequently, substantially odor free air is expelled from the vacuum cleaner during the vacuuming process. In one embodiment, the post exhaust gas filter is the only or primary gas filter in the filtering system. In another embodiment, the post exhaust gas filter is a secondary gas filter in the filtering system. In still another embodiment, the post exhaust gas filter can be removed from the vacuum cleaner without having to remove one or more other filters of the filtering system. As a result, the post exhaust gas filter can be replaced as needed independently of the other filters of the filtering system. In yet another embodiment, the gas filter includes a gas absorbing substance such as, but not limited to, activated carbon, activated charcoal, lava rocks, and/or baking soda. In still yet another embodiment, the gas filter includes one or more mats, or woven and/or non-woven materials impregnated with one or more gas absorbing substances. In a further embodiment, the gas filter includes one or more gas absorbing substances in the form of a resin and/or granules. In one aspect of this embodiment, the resin and/or granules are contained in an air permeable device such as, but not limited to, a ventilative bag, ventilative container and/or the like. In still a further embodiment, the gas filter includes one or more gas absorbing substances impregnated in a textile material.
In accordance with yet a further aspect of the invention, the filtering system includes a post exhaust air freshener. The post exhaust air freshener is designed to emit pleasant odors in the air exiting the vacuum cleaner. In one embodiment, the post exhaust air freshener can be removed and replaced from the vacuum cleaner without having to remove one or more filters of the filtering system. As a result, the post exhaust air freshener can be replaced as needed independently of the filters of the filtering system.
In accordance with still a further aspect of the present invention, the filtering system includes a filter liner to enable more convenient disposal of large particles that have fallen to the base or bottom of the low velocity chamber. In prior canister type vacuum cleaners, large particles accumulated at the bottom of the low velocity chamber during the vacuuming process. When the filters were replaced, the filters were removed and the bottom portion of the canister had to be carried out to a garbage can or other disposal area to be emptied. The carrying of the canister was both inconvenient and difficult. In addition, the emptying of the canister caused dust and other types of particles to be scattered about resulting in the individual being exposed to unwanted particles. After the canister was emptied, the user then had to wipe and clean the interior of the canister prior to reuse, thereby exposing the user to more particles and dust. The filter liner is designed to collect the particles that have fallen to the base or bottom of the low velocity chamber. As a result, the liner need only be removed with the filters to remove all the particles in the canister. The liner can be closed to minimize dust escaping during the filter replacement and disposal process. The liner also maintains the cleanliness of the inside of the canister thereby eliminating the need to clean the canister by hand after every disposal of the liner and filter. In one embodiment, the liner is made of a flexible material so as to be easily placed in the low velocity chamber. In one aspect of this embodiment, the liner is made of a cellulose material or paper that is coated on at least one side with a plastic film or other dust impenetrable film. In another aspect of this embodiment, the liner is made of a flexible plastic material. In another embodiment, the liner is connected to or secured to one or more filters of the filter system. In one aspect of this embodiment, the liner is connected to one or more filters by a melted seam, adhesive, and/or stitching.
In accordance with yet a further aspect of the present invention, the vacuum cleaner includes a removable canister to facilitate in the convenient disposal of dust and debris collected in the low velocity chamber. In prior canister type vacuum cleaners, the whole base portion of the vacuum cleaner had to be transported to a garbage can, lifted, and then turned over to dispose of the dust and debris that had collected in the low velocity chamber. Due to the bulkiness of the canister, the process of disposal of the dust and debris was not convenient and, at often times, difficult. The vacuum cleaner of the present invention overcomes this problem by designing a canister type vacuum cleaner that includes a lower canister that can be easily separated from the rest of the vacuum cleaner to enable a user to easily and conveniently dispose of dust and debris that has collected in the low velocity chamber. In one embodiment, the removable lower canister includes a handle. The handle allows a user to easily grasp the lower canister for convenient removal and reinsertion of the canister. The handle also makes is easier for the user to carry the low canister to a garbage can or other disposal area. In another embodiment, the lower canister is designed to be slidably removable from the vacuum cleaner when the top portion of the vacuum cleaner is lifted and/or removed.
In accordance with another aspect of the invention, the low velocity chamber of the vacuum cleaner includes an inlet nozzle that directs particle containing air about the filters in the low velocity chamber. The inlet nozzle, in effect, facilitates in the cyclonic air paths in the low velocity chamber. The inlet nozzle also directs the entering air about the filters in the low velocity chamber as opposed to directly at the filters. In prior canister vacuum cleaners, the low velocity chamber included an opening on one side of the chamber wall to allow entry of incoming air. The incoming air was directed at the filters and then began its cyclonic pathway. As a result, the area on the filter that was in the path of the incoming air prematurely became clogged with particles thereby reducing the efficiency and life of the filter. The inlet nozzle of the present vacuum cleaner overcomes this problem by causing the incoming air to immediately begin a cyclonic pathway about the filters thereby resulting in a more uniform distribution of particles about the filter during the filtering process. In one embodiment, the inlet nozzle is positioned at or close to the base of the low velocity chamber and extends into the interior of the low velocity chamber. The positioning of the inlet nozzle functions as a barrier to large particles that have fallen to the base of the low velocity chamber from continuing to circulate in the low velocity chamber. As a result, less particles are restirred in the low velocity chamber thereby increasing the efficiency and effectiveness of the filters in the low velocity chamber.
In accordance with still another aspect of the invention, the vacuum cleaner includes an air exhaust that increases the efficiency of air flow through the vacuum cleaner. Prior canister vacuum cleaners directed filtered air through several openings positioned about the perimeter of the motor housing. It has been found that by directing all of the filtered air through a single opening, the throughput efficiency of the air is increased. In one embodiment, a motor housing is included about the motor and fan of the vacuum cleaner and includes a single opening for allowing the filtered air to exit the housing. In another embodiment, an expanding air passageway is connected to the opening of the motor housing. The expanding passageway at least partially directs filtered air from the motor housing to the external housing of the vacuum cleaner. In one aspect of this embodiment, the width of the expanding passageway at least partially expands along the length of the expanding passageway. In another aspect of this embodiment, the height of the expanding passageway at least partially expands along the length of the expanding passageway. In still another embodiment, the expanding air passageway directs filtered air into an exhaust chamber that includes one or more filters and/or air fresheners. In one aspect of this embodiment, the opening into the exhaust chamber is greater than the opening of the motor housing. In another aspect of this embodiment, the filter in the exhaust chamber includes a gas filter. In still another aspect of this embodiment, the filter in the exhaust chamber includes a particle filter. In still yet another aspect of this embodiment, the exhaust chamber includes an air freshener. In yet another aspect of this embodiment, the exhaust chamber includes a single opening to expel filtered air from the external housing of the vacuum cleaner. In one specific design, the opening in the exhaust chamber is similar in size to the opening into the low velocity chamber. In another specific design, the opening in the exhaust chamber is similar in size to the opening between the motor housing and expanding air passageway.
The primary object of the present invention is the provision of a novel filter system that can effectively filter out a majority of the particles entrained in the air and/or to remove odors in the air as the air passes through the filter without causing a large pressure drop and can be easily used in a vacuum cleaner such as a canister type vacuum cleaner.
Another and/or alternative object of the present invention is the provision of a filter system which can be easily changed.
Still yet another and/or alternative object of the present invention is the provision of a filter system which has a large area.
Yet another and/or alternative object of the present invention is the provision of a conical filter system adapted to be held in a nested position.
Still a further and/or alternative object of the present invention is the provision of a filter system which is fixedly located in the reduced air velocity chamber of a vacuum cleaner so that low velocity air passes through the filter system to provide resident time to contact the large surface area of the filter system so as to remove particles from the air being cleaned by the vacuum cleaner.
A further and/or alternative object of the present invention is a vacuum cleaner which includes using a particle filter in combination with a gas filter to remove both particles and unwanted gases from the air.
Another and/or alternative object of the present invention is a vacuum cleaner designed to minimize the air pressure drop throughout the vacuum cleaner thereby reducing the need for a large motor to draw in and expel air from the vacuum cleaner.
Still another and/or alternative object of the present invention is the design of a compact and portable vacuum cleaner which can be easily moved to different rooms by a user.
Yet another and/or alternative object of the present invention is a vacuum cleaner that includes a liner to conveniently remove settled particles and debris in the vacuum cleaner.
Still yet another and/or alternative object of the present invention is a vacuum cleaner that has a removable canister to facilitate in easier cleaning of the vacuum cleaner.
A further and/or alternative object of the present invention is a vacuum cleaner that filters gases from the exhaust of the vacuum cleaner.
Still a further and/or alternative object of the present invention is a vacuum cleaner that includes a particle filter having a rib and trough profile that efficiently removes small particles entrained in the air.
Another and/or alternative object of the present invention is a vacuum cleaner that freshens air prior to exhausting the air from the vacuum cleaner.
Yet another and/or alternative object of the present invention is a vacuum cleaner that has a filter support that causes ribs and trough sections to be formed in a filter when the filter at least partially collapses on the filter support during operation of the vacuum cleaner.
Still another and/or alternative object of the present invention is a vacuum cleaner that has a filter to prevent large particles from entering the motor chamber of the vacuum cleaner.